This function is used to "snap" the instance to a grid of a given size. It will be snapped to the nearest corresponding position on the "invisible" grid that the hsnap and vsnap values define.
move_snap( hsnap, vsnap );
|hsnap||The horizontal snapping (the size in pixels between 'cells').|
|vsnap||The vertical snapping (the size in pixels between 'cells').|
if !place_snapped(32, 32)
The above code checks all instances of "obj_Pieces" to see if they are snapped to a grid of 32x32 pixels, and if they are not it snaps them to the nearest position in that grid.